I agree with the other posters. Generally, there are people hanging around near the gates attempting to sell remaining days on old tickets. There is no way to check to see if the tickets actually have days remaining on them, so often they are selling worthless tickets. You will not find this out until you try to go through the turnstile.
The other place you might see this advertised is on timeshares on the way to Florida. The tickets are cheap, but you buy them by sitting through a very high-pressure sales presentation for hours first. So you might end up with a three-day ticket after eight hours and possibly a $500 a month timeshare.
The only way to really buy safe tickets is through a real ticket broker or through Disney. Sometimes companies such as Small World Travel can get a small discount; Undercover Tourist is another place that has discounted or extra days on tickets. The other place I've heard of discounted tickets is at Costco or Sam's, or you can get them at some Wal-Mart stores in Kissimee and Orlando (4444 West Vine Street, Kissimmee, 8101 John Young Parkway in Orlando). Sometimes Disney itself offers discounts if you buy tickets online and in advance.
In any case, it's hard to save money on the tickets themselves. It's easier to save money on food and lodging though. Try the links below.
Source(s):
http://www.themouseforless.com/tripplann…
http://www.mousesavers.com/